Below shows a general form of DTD element declaration. Which of the following best describe this declaration? Assume there is no error in the code segment. Select one: The parent element "xyz" can have at most one "abc" element. O You can define one or more "abc" elements. The parent element "xyz" needs to have at least one "abc" element. O None of these answers. Which of the following statement is true about the below code segment? Select one: O It is a command to extract the xml data element within the "a" tag O None of these answers. O It is a command to extract the xml attribute value O It is a command to select the constant value "a